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<Title>DG Scramjet Data</Title>
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<h1>DG-S Technical Specification</h1>
<h3>Scramjet Subsystem</h3>

<p>
The Delta-glider is equipped with two scramjet engines located at the underside of the fuselage which
can be used during the atmospheric phase of Earth ascents/descents to preserve propellant
for the primary engine system.
<p>
To provide sufficient compression of the airstream in the diffusor, the scramjets should only be operated at velocities M > 3.0. Takeoff and initial climb phase therefore require the use of the DG main engines.
<p>

<table cols=3 cellspacing=0 border=1 style="width:100%">

<thead>

<tr>
<th rowspan=2>Parameter</th>
<th colspan=2 align=center>Flight model</th>
</tr>
<tr>
<th align=center style="border-top: none">easy</th>
<th align=center style="border-top: none">complex</th>
</tr>

<tbody>

<tr>
<td>Intake area</td>
<td>2 x 1.0 m<sup>2</sup></td>
<td>2 x 1.0 m<sup>2</sup></td>
</tr>

<tr>
<td>Burner temperature limit</td>
<td>3500 K</td>
<td>3200 K</td>
</tr>

<tr>
<td>Propellant</td>
<td>Hydrocarbon<sup>[1]</sup></td>
<td>Hydrocarbon<sup>[2]</sup></td>
</tr>

<tr>
<td>Fuel heating value (in air)</td>
<td>3.5&middot;10<sup>8</sup>J/kg</td>
<td>2.0&middot;10<sup>8</sup>J/kg</td>
</tr>

<tr>
<td>Fuel pump capacity</td>
<td>2.0 kg/s (max)</td>
<td>3.0 kg/s (max)</td>
</tr>

<tr>
<td>Thrust rating (v=Mach 4, alt=10km)</td>
<td>390 kN per engine</td>
<td>340 kN per engine</td>
</tr>

<tr>
<td>TSFC (v=Mach 4, alt=10km)</td>
<td>0.0051 kg kN<sup>-1</sup> s<sup>-1</sup></td>
<td>0.0088 kg kN<sup>-1</sup> s<sup>-1</sup></td>
</tr>

<tr>
<td>Fuel capacity</td>
<td>4.0&middot;10<sup>3</sup> kg<sup>[3]</sup><br>
10.4&middot;10<sup>3</sup> kg<sup>[4]</sup></td>
<td>4.0&middot;10<sup>3</sup> kg<sup>[3]</sup><br>
10.4&middot;10<sup>3</sup> kg<sup>[4]</sup></td>
</tr>

<tr>
<td>Operational speed</td>
<td>Mach 3.0 &le; v &le; Mach 7.3</td>
<td>Mach 3.0 &le; v &le; Mach 7.3</td>
</tr>

<tr>
<td>Operational altitude</td>
<td>10 km &le; h &le; 40 km</td>
<td>10 km &le; h &le; 40 km</td>
</tr>

<tr>
<td>Sustained speed (level flight)</td>
<td>Mach 4.3 (alt=10km)<br>Mach 7.5 (alt=20km)</td>
<td>Mach 3.9 (alt=10km)<br>Mach 7.3 (alt=20km)</td>
</tr>
</table>

<sup>[1]</sup>) magically enhanced<br>
<sup>[2]</sup>) enhanced<br>
<sup>[3]</sup>) configuration A<br>
<sup>[4]</sup>) configuration B
<p>
<img src="DGscram2.gif">
<br><i>Fig. 1: DG scramjet TSFC vs. Mach number at ambient density 0.43 kg/m<sup>3</sup> and ambient temperature 225 K (corresponding to altitude 10 km in standard atmosphere).</i>

<!--
<p>
<img src="DGscram3.gif">
<br><i>Fig. 2: Diffuser, combustion and exhaust temperatures vs. Mach number.</i>
-->

<p>
<img src="DGscram1.gif">
<br><i>Fig. 3: DG scramjet single engine thrust vs. Mach number.</i>

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